[jimbo44]

I've posted about getting better efficiency before, and I've always applied the suggestions to the equation.  I have a manifold that covers about as much as the bottom without it being a false.  I have a sparge arm that very slowly and evenly distributes.  The only question I have.

Does anyone FLY sparge with a rectangular cooler?  If so, do you use a manifold, and Sparge arm?  If so, would you please post a picture of your system and your average efficiency.  Just curious whether I should bag fly sparging with a rectangular cooler or if my system is missing something.  I don't know why, but i really want to nail fly sparging.

I understand the million variables.  Just want to see your system.  Want to know I'm lautering as best i can before I worry about some of the other variables.  I already sparge for 30 to 45 minutes with my PH between 5.2 and 5.6

[Thirsty_Monk]

I have a round cooler but...

I do not think that sparge arm is necessary.
You already have it so use it.

When I lauter I "rake" top portion of grain bed without disturbing filtering capacity.
All you need for filtering is 3 inch grain bed.

If you can measure your run offs you want to run about 45 sec per 1 quart.
Slower runoff more sugar you will extract.

[MDixon]

I fly sparge with a rectangular, but in reality I runoff as a batch the first runnings and then begin to fly. I think the continual addition of water is a waste of time unless you find you are compacting the grainbed and so I add as much water as possible and then once that drops some add again. I have a super sophisticated Armstrong system with manual controls 

http://www.ipass.net/mpdixon/ (see setup and mashing techniques)

My efficiency is always in excess of 85%, but I rarely make beers topping 1.070 anymore. I suspect at 1.100 I'd be down in the 75%-80% range.